Gamma Doradus variables are variable stars which display variations in luminosity due to non-radial pulsations of their surface. The stars are typically young, early F or late A typemain sequence stars, and typical brightness fluctuations are 0.1 magnitudes with periods on the order of one day. This class of variable stars is relatively new, having been first characterized in the second half of the 1990s, and details on the underlying physical cause of the variations remains under investigation.
The star 9 Aurigae was first noticed to be variable in 1990. However, none of the currently-accepted explanations were adequate: it pulsated too slowly and was outside of the Delta Scutiinstability strip, and there was no evidence for any eclipsing material, although Gamma Doradus and HD 96008 were noted to be similar.[2] These three stars, as well as HD 224638, were soon hypothesized to belong to a new class of variable stars in which variability was produced by g-mode pulsations rather than the p-mode pulsations of Delta Scuti variables.[3]HD 224945 and HD 164615 were noticed to be similar as well, while HD 96008 was ruled out on the basis of its more regular period.[4]Eclipses and starspots were soon ruled out as the cause of the Gamma Doradus' variability,[5] and the variability of 9 Aurigae was confirmed to be caused by g-mode pulsations a year later, thus confirming the stars as the prototypes of a new class of variable stars.[6] Over ten more candidates were quickly found,[7] and the discoverers dubbed the group the Gamma Doradus stars, after the brightest member and the first member found to be variable.[8]
^Krisciunas, K.; Handler, G. (1995). "A List of Variable Stars Similar to gamma Dor". Information Bulletin on Variable Stars. 4195: 1. Bibcode:1995IBVS.4195....1K.
^Krisciunas, K. (1995). "What is known and not known about Gamma Doradus stars". Delta Scuti Star Newsletter. 9: 17. Bibcode:1995DSSN....9...17K.
^ abSamus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1: 02025. Bibcode:2009yCat....102025S.
^ abcdefghijklmnopqrAerts, C.; Eyer, L.; Kestens, E. (1998). "The discovery of new gamma Doradus stars from the HIPPARCOS mission". Astronomy and Astrophysics. 337: 790. Bibcode:1998A&A...337..790A.
^Breger, M.; Handler, G.; Garrido, R.; Audard, N.; Beichbuchner, F.; Zima, W.; Paparo, M.; Li, Z.; Jiang, S.; Liu, Z.; Zhou, A.; Pikall, H.; Stankov, A.; Guzik, J. A.; Sperl, M.; Krzesinski, J.; Ogloza, W.; Pajdosz, G.; Zola, S.; Serkowitsch, E.; Reegen, P.; Rumpf, T.; Schmalwieser, A. (1996). "A new Gamma Doradus star, HD 108100". Delta Scuti Star Newsletter. 10: 24. Bibcode:1996DSSN...10...24B.
^Eyer, L.; Aerts, C. (2000). "A search for new gamma Doradus stars in the Geneva photometric database". Astronomy and Astrophysics. 361: 201. arXiv:astro-ph/0011061. Bibcode:2000A&A...361..201E.
^ abKaye, A. B.; Bagnuolo, W. G.; Hall, D. S.; Henry, G. W. (1998). "Recent Periodic Variations in Three Gamma Doradus Variables". In Bradley, P. A.; Guzik, J. A. (eds.). A Half Century of Stellar Pulsation Interpretation: A Tribute to Arthur N. Cox. Conference held in Los Alamos, NM 16-20 June 1997. ASP Conference Series. Vol. 135. pp. 497–501. Bibcode:1998ASPC..135..497K.
^Henry, Gregory W.; Fekel, Francis C. (2002). "Six New γ Doradus Stars". Publications of the Astronomical Society of the Pacific. 114 (799): 988–998. Bibcode:2002PASP..114..988H. doi:10.1086/341785.
^ abDolez, N.; Vauclair, S.; Michel, E.; Hui-Bon-Hoa, A.; Vauclair, G.; Le Contel, D.; Mathias, P.; Poretti, E.; Amado, P. J.; Rainer, M.; Samadi, R.; Baglin, A.; Catala, C.; Auvergne, M.; Uytterhoeven, K.; Valtier, J.-C. (2009). "HD 51106 and HD 50747: an ellipsoidal binary and a triple system observed with CoRoT". Astronomy and Astrophysics. 506 (1): 159–165. arXiv:0909.5135. Bibcode:2009A&A...506..159D. doi:10.1051/0004-6361/200911903.
^Bruntt, H.; Catala, C.; Garrido, R.; Rodríguez, E.; Stütz, C.; Knoglinger, P.; Mittermayer, P.; Bouret, J. C.; Hua, T.; Lignières, F.; Charpinet, S.; Van't Veer-Menneret, C.; Ballereau, D. (2002). "Abundance analysis of targets for the COROT/MONS asteroseismology missions". Astronomy and Astrophysics. 389 (1): 345–354. arXiv:astro-ph/0203305. Bibcode:2002A&A...389..345B. doi:10.1051/0004-6361:20020549.
^Uytterhoeven, K.; Mathias, P.; Poretti, E.; Rainer, M.; Martín-Ruiz, S.; Rodríguez, E.; Amado, P. J.; Le Contel, D.; Jankov, S.; Niemczura, E.; Pollard, K. R.; Brunsden, E.; Paparó, M.; Costa, V.; Valtier, J.-C.; Garrido, R.; Suárez, J. C.; Kilmartin, P. M.; Chapellier, E.; Rodríguez-López, C.; Marin, A. J.; Aceituno, F. J.; Casanova, V.; Rolland, A.; Olivares, I. (2008). "The γ Doradus CoRoT target HD 49434". Astronomy and Astrophysics. 489 (3): 1213–1224. arXiv:0807.0904. Bibcode:2008A&A...489.1213U. doi:10.1051/0004-6361:200809992.
^Rodriguez, E.; Zerbi, F. M. (1995). "A long period early F-type variable: HR8799". Information Bulletin on Variable Stars. 4170: 1. Bibcode:1995IBVS.4170....1R.